I'm having lock ups without any cheats at all. Also my DS is beeping at me after I play the game for a few minutes. I have the latest Firmware.

Edit: Ah, I'm stupid. The beeping was the alert for getting chased by a monster. It sounded a lot like a computers alert beeps when you are a certain distance away from the monster, so I assumed it was the DS hardware. Lock ups have stopped since I trimmed the rom.